Three famous former Blue Peter presenters have shared their memories of the children's programme, as they prepare to celebrate its 50th anniversary next week.

Peter Purves, Valerie Singleton and John Noakes will will feature in a a special edition of the BBC1 show on Thursday, to commemorate the first time it aired on October 16 1958.

Asked to recall their favourite moments, the trio chose the time Princess Anne went on safari with Singleton and then visited the studio in 1971, where she reportedly took a shine to Noakes.

In an interview with Radio Times, Singleton, 71, said: "It was surreal wandering along a beach with Princess Anne. We were near Mombasa, and she had the paparazzi crawling through bushes with mega-lenses."

Noakes, 74, added: "When she came to the studio, she had beautiful eyes and nice long hair over her shoulders, and Val said, 'I think she fancies you.' I said, 'Yeah, and I fancy her.' I could have been King John I or II or III or whatever."

Another special memory was the time Noakes climbed Nelson's Column in 1977, which was one of the most daring stunts performed on Blue Peter.

Singleton said: "It's incredible. It still amazes me when I see that. I think that's the bravest thing you did, to be quite honest. If you'd fallen off that, you'd have been killed."

Noakes said: "I think I saw somebody in Glasgow waving."

The trio also recognised the difficult relations they shared with Blue Peter's legendary editor, Biddy Baxter.

Noakes said: "She was a very, very difficult woman."

Purves, 69, added: "But the programme succeeded - and I've said this many times - because of her, not in spite of her. She absolutely ruled it; I didn't always agree with her views, but she was right."

Purves and Singleton also recalled that their co-host during the 60s and 70s could be difficult to work with.

Purves said: "I love him to bits, but he did embarrass us from time to time. He does go into "John Noakes mode". He's embarrassed by his own views, so he becomes stupid about it instead."

Singleton added: "He could go over the top and go too far."

The trio will be joined by presenters from the past five decades for Blue Peter's Live 50th Birthday on Thursday, which features an appearance from the Queen and will be filmed in part at Buckingham Palace.